How to locate an element based on their label in selenium

How to locate an element based on their label.
Some time it difficult to locate an element usiing DOM, HTML and xpath. In that case we use to locate the element with the
help of their lables.

For example : Go to yahoo login page

selenium.open("https://login.yahoo.com");

Based on the lable "Yahoo ! ID" we will read the text box and type in.

selenium.type("css=label:contains(\"Yahoo! ID\")+input", "niraj");

Based on the lable "Password" we will locate the text box for passowrd and type in.

selenium.type("css=label:contains(\"Password\")+input", "pass");

Go to yahoo registrantion page.

selenium.open("https://edit.yahoo.com/registration?.intl=us");

Based on Name label we will type in First Name text box. 

selenium.type("css=label:contains(\"Name\")+div>input", "niraj");

Based on Name label we will  type in Last name text box.

selenium.type("css=label:contains(\"Name\")+div>input+input", "kumar");

Based on Gender lable we will select the gender from drop down.

selenium.select("css=label:contains(\"Gender\")+div>select", "label=Male");

Based on Birthday lable we will select the month from drop down.

selenium.select("css=label:contains(\"Birthday\")+div>select", "label=January");

Based on Birthday lable we will type the date in date text box.

selenium.type("css=label:contains(\"Birthday\")+div>select+input", "2");

Based on Birthday lable we will type the year in year text box.

selenium.type("css=label:contains(\"Birthday\")+div>select+input+input", "1982");

Based on country lable we will select India in country drop down box.

selenium.select("css=div>label:contains(\"Country\")+div>select", 
"label=India");

+ Is used to point the element on the same node in tree of css.
<label class="label" for="name">Name</label>
<div class="collection" id="name">
<input type="text" title="First Name" name="firstname" id="firstname" value="" size="32" maxlength="32" class="" autocomplete="off">
<input type="text" title="Last Name" name="secondname" id="secondname" value="" size="32" maxlength="32" class="" autocomplete="off">
</div>
to access firstname text box
selenium.type("css=label:contains(\"Name\")+div>input", "niraj");
to access secondname its the same label of div but on the second place
selenium.type("css=label:contains(\"Name\")+div>input+input", "kumar");


> Is used to point the element one node down in the tree of css.
to access firstname text box
selenium.type("css=label:contains(\"Name\")+div>input", "niraj");